It is proposed to compare the toxic action of ozone in the atmosphere to that of the intravenous injection of ozonides and hydroperoxides. A simple apparatus of new design will be used to provide atmospheres of controlled concentrations of ozone for toxicity studies. Effects of these compounds on vitamin E lecithin-cholesterol acyl transferase activity (LCAT) and prostaglandins in serum, heart and lung will be compared. Progressive effects of the toxic reactions will also be studied by ultrastructure analyses of lung tissue. One objective of these studies is to define the relationship between serum LCAT activity and the toxic effect of oxidants. The fate of ozonides and peroxides injected intravenously will be studied via the use of radioactive compounds in order to elucidate the mechanism of the detoxification process by which these compounds and ozone are catabolized or their toxic effects are manifested.